Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA.
Cancer. 2011 Aug 1;117(15):3502-8. doi: 10.1002/cncr.25851. Epub 2011 Feb 1.
The clinical benefit of postoperative mediastinal radiation for completely resected Masaoka stage 2 thymoma remains controversial. Due to its indolent nature and infrequent recurrences, no study has definitively determined the optimal approach.
We retrospectively reviewed 175 consecutive patients who underwent thymic resection from January 1990 to July 2008 at the University of Pennsylvania. The primary endpoint was local recurrence, defined as recurrence within the surgical bed, treated by resection alone versus resection plus radiation. Patients with high recurrence risk were referred for adjuvant radiotherapy.
Seventy-four Masaoka stage 2 patients were resected; 62 underwent complete resections with adequate postsurgical follow-up. Thirty-seven patients received adjuvant radiotherapy and 25 patients were observed. The median radiation dose was 5040 cGy. The median follow-up for all patients was 52 months. The local recurrence rate was 3.2%. The proportion of recurrences in patients observed after surgery was 8% versus 0% in those who received adjuvant radiotherapy (P = .15). Size was not an independent predictor of recurrence (P = .81). The tumor-related death rate was 0%, and overall death rate was 3.2%. One death occurred in each group, observation, and radiation. There were no grade 3 or 4 complications with radiation.
Recurrence rates were low following resection of stage 2 thymoma either with or without adjuvant radiotherapy. Adjuvant radiotherapy, although well-tolerated, did not significantly decrease the local relapse rate. Differences may be observed in future studies of patients who are at higher risk for local recurrence, based on completeness of resection, World Health Organization histology, and tumor size.
完全切除的 Masaoka 分期 2 型胸腺瘤术后纵隔放疗的临床获益仍存在争议。由于其惰性特征和复发频率较低，尚无研究明确最佳治疗方法。
我们回顾性分析了 1990 年 1 月至 2008 年 7 月期间在宾夕法尼亚大学接受胸腺切除术的 175 例连续患者。主要终点是局部复发，定义为手术床内复发，仅行切除术与切除术加放疗的治疗效果。高复发风险的患者被推荐行辅助放疗。
74 例 Masaoka 分期 2 型患者接受了切除术；62 例患者行完全切除术且术后随访充分。37 例患者接受了辅助放疗，25 例患者仅行观察。中位放疗剂量为 5040 cGy。所有患者的中位随访时间为 52 个月。局部复发率为 3.2%。术后观察患者的复发比例为 8%，而接受辅助放疗的患者为 0%（P =.15）。肿瘤大小不是复发的独立预测因素（P =.81）。肿瘤相关死亡率为 0%，总死亡率为 3.2%。每组各有 1 例死亡，观察组和放疗组各 1 例。放疗后无 3 级或 4 级并发症。
无论是否行辅助放疗，切除 Masaoka 分期 2 型胸腺瘤后复发率均较低。辅助放疗虽然耐受良好，但并未显著降低局部复发率。基于手术切除的完整性、世界卫生组织组织学和肿瘤大小，在未来对局部复发风险较高的患者进行研究时，可能会观察到不同的结果。
